To quote you:

... That's not how periods work.

I'm a girl, I know how periods work. They don't go MIA for a couple of months without reason. Their absence can be caused by anorexia, serious hormonal issues, serious ovarian issues or pregnancy.

If you haven't had one in a long time, something is really wrong. Hell, if you miss your period for any time at all, you should really go see a doctor. Why do women freak out when their period is two weeks late? It means something's up.

Also, you don't get it on the same day, but around the same day. The cycle lasts 28 days.

Are you a girl? I know you're hobbitqueen, but your comment is just so bizarre.

If you usually get it on the same day and then it stops for a couple of months and starts back up again

That doesn't happen. It's not normal. It's very very very out of the ordinary and very very alarming. Like, that's its whole thing, that it's there every month to let you know you're not pregnant.

I'm bewildered. Either you're an awfully misinformed girl (who should see a doctor, if you're speaking from experience), or a guy pretending to know what he's talking about.